Fast Bioremediation Eases Site Development in Boston

Underground storage tank (UST) leaks from a former gas station contaminated shallow ground water under a parking lot for a commercial building.  The UST contamination was found during trenching for utilities.  As the presence of contamination prevented further property development, fast remediation was important to the stakeholders.

The size of ground water plume that resulted from leaching soil contaminants was estimated to be 5,000 square feet.    The contamination was mainly diesel-range petroleum constituents, with the highest concentrations in the aliphatic range, but there were also scattered detections of xylene, toluene, and ethylbenzene.

Petrox bioremediation was implemented in the ground water.  Three units of Petrox (165 gallons) were injected into the contaminated ground water through vertical injection wells located up gradient of the monitoring wells.

After a single inoculation of Petrox, the contaminant concentrations were reduced across the property.  The following table shows the overall reduction in both the volatile and semi-volatile range hydrocarbons.

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Fast, Easy Drainage Ditch Cleanup

Petrox bioremediation of surface spills and TPH accumulation in drainage ditches and maintenance areas is simple. Using a simple manual sprayer, the Petrox is applied to the soil surface. The Petrox microbes begin bioremediation immediately to enhance natural digestion of the petroleum, like probiotics for petroleum destruction.  Unlike detergents that was the visible oil away, Petrox microbes destroy the all of the oil.

The following chart and table show the results of the application of Petrox to petroleum-contaminated soil in a drainage ditch. After about 60 days, the TPH concentration was reduced by 67% in one location and over 90% in three locations.  A second application to the 30 ft. north area reduced the concentration even more.

The problem was solved for a total Petrox cost of $600.

houston soil treatment chart houston soil treatment table

 

 

 

Field Bioremediation Rates For Petroleum and Solvents

The success of bioaugmentation depends on effective distribution of the beneficial microbes.  If the target population is achieved, the remediation rate ranges from 50% to over 99% removal.  The rate appears to be independent of the contaminant starting concentrations.  This indepedence is the advantage of bioaugmentation.  Through bioaugmentation the density of beneficial organisms is sufficient for frequent reactions with high or low contaminant levels.  The following chart shows the results of a single application of bioaugmentation at 11 sites in different states, with different contaminants.

remediation rates with bioaugmentation

 

The chart also suggests that the results are not time dependent.  The apparent time independence may be because the reactions are completed early and because these were grid applications with the monitoring locations within the bioaugmented area instead of downgradient where the results would depend on dispersion rates.